Multiple Choice
Which of the following sentences is written in the active voice?
(1 point)
Responses
The wedding dress was sewn by Katie.
The wedding dress was sewn by Katie.
The red barn was painted by the farmer.
The red barn was painted by the farmer.
The boy jumped on the trampoline.
The boy jumped on the trampoline.
The chocolate cake will be served to the queen.
The boy jumped on the trampoline.
Which of the following sentences is written in the passive voice?
(1 point)
Responses
Charlie ran down the street.
Charlie ran down the street.
The delicious bread is baked by Mr. Jillin.
The delicious bread is baked by Mr. Jillin.
The plane will fly at five o’clock.
The plane will fly at five o’clock.
Kristin played with her dolls.
Kristin played with her dolls.
The delicious bread is baked by Mr. Jillin.
To indent the first line of a paragraph, which key should you use?
(1 point)
Responses
Shift key
Shift key
Tab key
Tab key
Enter key
Enter key
Space key
Tab key
The _________________ key is used to create spaces between lines within a document.
(1 point)
Responses
Enter
Enter
Tab
Tab
Shift
Shift
Ctrl
Enter
Thanks!
You're welcome! If you have any more questions, feel free to ask.
Use the chemical reaction to answer the question.
CaCO3→CO2+CaO
A scientist heats 30 grams of calcium carbonate (CaCO3
) in the chemical reaction shown. What is the total mass of the products?
To determine the total mass of the products in the chemical reaction, we need to know the molar masses of the reactant and products.
The molar mass of CaCO3 (calcium carbonate) is calculated as follows:
molar mass of Ca = 40.08 g/mol
molar mass of C = 12.01 g/mol
molar mass of O = 16.00 g/mol
So, molar mass of CaCO3 = (40.08 g/mol) + (12.01 g/mol) + (16.00 g/mol) + (16.00 g/mol) + (16.00 g/mol) = 100.09 g/mol
According to the balanced chemical equation, 1 mole of CaCO3 produces 1 mole of CO2 and 1 mole of CaO.
The molar mass of CO2 (carbon dioxide) is calculated as follows:
molar mass of C = 12.01 g/mol
molar mass of O = 16.00 g/mol
So, molar mass of CO2 = (12.01 g/mol) + (16.00 g/mol) + (16.00 g/mol) = 44.01 g/mol
The molar mass of CaO (calcium oxide) is calculated as follows:
molar mass of Ca = 40.08 g/mol
molar mass of O = 16.00 g/mol
So, molar mass of CaO = (40.08 g/mol) + (16.00 g/mol) = 56.08 g/mol
Now, we can calculate the total mass of the products:
mass of CO2 = (1 mole of CO2) * (44.01 g/mol) = 44.01 g
mass of CaO = (1 mole of CaO) * (56.08 g/mol) = 56.08 g
Therefore, the total mass of the products (CO2 + CaO) in the reaction is:
44.01 g + 56.08 g = 100.09 g
A scientist heats 30 grams of calcium carbonate (CaCO3
) in the chemical reaction shown. What is the total mass of the products?
(1 point)
Responses
30 grams
30 grams
15 grams
15 grams
60 grams
60 grams
10 grams
To find the total mass of the products, we need to use stoichiometry and the molar masses of the reactant and products.
The molar mass of CaCO3 (calcium carbonate) is calculated as follows:
molar mass of Ca = 40.08 g/mol
molar mass of C = 12.01 g/mol
molar mass of O = 16.00 g/mol
So, molar mass of CaCO3 = (40.08 g/mol) + (12.01 g/mol) + (16.00 g/mol) + (16.00 g/mol) + (16.00 g/mol) = 100.09 g/mol
According to the balanced chemical equation, 1 mole of CaCO3 produces 1 mole of CO2 and 1 mole of CaO.
The molar mass of CO2 (carbon dioxide) is calculated as follows:
molar mass of C = 12.01 g/mol
molar mass of O = 16.00 g/mol
So, molar mass of CO2 = (12.01 g/mol) + (16.00 g/mol) + (16.00 g/mol) = 44.01 g/mol
The molar mass of CaO (calcium oxide) is calculated as follows:
molar mass of Ca = 40.08 g/mol
molar mass of O = 16.00 g/mol
So, molar mass of CaO = (40.08 g/mol) + (16.00 g/mol) = 56.08 g/mol
To find the moles of CaCO3 in 30 grams of CaCO3, we divide the mass by the molar mass:
30 g CaCO3 / (100.09 g/mol) = 0.2998 moles of CaCO3
Since the ratio of moles in the balanced equation is 1:1:1, we also have 0.2998 moles of CO2 and 0.2998 moles of CaO.
To find the masses of the individual products, we multiply the moles by their respective molar masses:
mass of CO2 = (0.2998 mol CO2) * (44.01 g/mol) ≈ 13.194 g
mass of CaO = (0.2998 mol CaO) * (56.08 g/mol) ≈ 16.816 g
Therefore, the total mass of the products (CO2 + CaO) is approximately:
13.194 g + 16.816 g = 30.01 g
So, the correct answer is approximately 30 grams.
What happens to atoms of Fe and O2 during the reaction?
(1 point)
Responses
They are lost.
They are lost.
They gain mass.
They gain mass.
They maintain their properties.
They maintain their properties.
They are rearranged.
They are rearranged.
They are rearranged.
Which is most likely to occur during a chemical reaction?(1 point)
Responses
New atoms are created.
New atoms are created.
Mass is conserved.
Mass is conserved.
The original substance maintains its properties.
The original substance maintains its properties.
Atoms of the original substance are lost.
Mass is conserved.
Chemical Reactions Quick Check
4 of 54 of 5 Items
Question
Use the chemical reaction to answer the question.
NaHCO3+HC2H3O2→NaC2H3O2+H2O+CO2
A student mixes baking soda (NaHCO3
) and acetic acid (HC2H3O2
) to produce a chemical reaction shown. Which statement about the reaction is correct?
(1 point)
Responses
Atoms of Na are destroyed during the reaction.
Atoms of Na are destroyed during the reaction.
Some atoms gain mass after the reaction.
Some atoms gain mass after the reaction.
There are more H atoms after the reaction.
There are more H atoms after the reaction.
The atoms of the reactants are regrouped during the reaction.
The atoms of the reactants are regrouped during the reaction.
Chemical Reactions Quick Check
5 of 55 of 5 Items
Question
Use the chemical reaction to answer the question.
2H2+O2→2H2O
There are four atoms of hydrogen (H
) before the reaction. How many atoms of hydrogen are present after the reaction?
(1 point)
Responses
2
2
4
4
8
8
5
5
There are four atoms of hydrogen (H) before the reaction. After the reaction, there are still four atoms of hydrogen.
So, the correct answer is 4.